In this study, toxicological safety (mutagenicity) and therapeutic potential (antimutagenicity)
of water extract of Centella asiatica Linn., were evaluated using the Allium cepa assay. The
mitotic index (MI) at 6.25% concentration of the extract decreased significantly from 3.13% to
2.05% after 24 h and 48 h, respectively, however, the MI increased significantly by 60% and
400% at 12.5% and 50.0% concentrations, respectively. There was total arrest of cell division
at 100% concentration after 24 h and 48 h of onion’s roots exposure to the water extract.
The chromosomal aberrations (CA) induced by the extract were not significantly different
from the negative control (p ≥ 0.05) at the tested concentrations. The mutagenic activity of
cyclophosphamide was significantly suppressed above 50% at the tested concentrations. These
results suggest non-genotoxic effect, and antimutagenic potency of water extract of C. asiatica
in A. cepa cells, being desirable characteristics of anticancer therapeutics.
A wide variety of skin disorders in children are encountered by doctors practising in tropical countries. While some of them are common and pose little difficulty in their management, a few are uncommon, run a protracted course and cause errors in diagnosis. Two patients--one with cutaneous tuberculosis and the other with chromomycosis--are described and illustrate the importance of early and prompt detection of disease in children.
Yaws was detected in a six-member family in the southern Malaysia state of Johor. This stresses the need to be vigilant against a long-forgotten disease of childhood which was of great public health concern in the past.
A 60 year old male presented with pruritus, excoriations and enlargement of several groups of lymph nodes associated with constitutional symptoms following the intake of an aspirin preparation. Lymph node biopsy established the diagnosis of angioimmunoblastic lymphadenopathy. The need to be aware of this condition is highlighted when patients present with clinical features suspicious of lymphoma.
This work investigates the development of a nanofabrication process to achieve high aspect-ratio nanostructures on quartz substrates using electron beam lithography (EBL) patterning and fluorinated plasma etching processes. An imaging layer of a poly(methyl methacrylate) bi-layer resist was spun coated on quartz substrate and exposed by an e-beam with the designed patterns of sub-100 nm feature sizes using a Raith-150 EBL patterning tool. Additive pattern transfer was employed by depositing a 40 nm thick Nichrome layer on the resist pattern using a metal evaporator which was later lifted off by soaking in acetone. Nichrome was employed as an etch mask and an Oxford Plasmalab 80Plus reactive ion etcher was used for the etching process. The etching process was carried out in a gas mixture of CHF(3)/Ar with a flow rate ratio of 50/30 sccm, pressure of 20 mTorr, radiofrequency power of 200 W and at room temperature. These etching process parameters were found to achieve a 10 nm min(-1) etch rate and tall vertical side walls profile. An aspect-ratio of 10:1 was achieved on 60 nm feature size structures.
This paper reports the rapid melt quenching technique preparation for the new family of bismuth-lead germanate glass (BPG) systems in the form of (GeO(2))(60)-(PbO)(40-) (x)-(½Bi(2)O(3))(x) where x = 0 to 40 mol%. Their densities with respect of Bi(2)O(3) concentration were determined using Archimedes' method with acetone as a floatation medium. The current experimental data are compared with those of bismuth lead borate (B(2)O(3))(20)-(PbO)(80-) (x)-(Bi(2)O(3))(x). The elastic properties of BPG were studied using the ultrasonic pulse-echo technique where both longitudinal and transverse sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. Experimental data shows that all the physical parameters of BPG including density and molar volume, both longitudinal and transverse velocities increase linearly with increasing of Bi(2)O(3) content in the germanate glass network. Their elastic moduli such as longitudinal, shear and Young's also increase linearly with addition of Bi(2)O(3) but the bulk modulus did not. The Poisson's ratio and fractal dimensionality are also found to vary linearly with the Bi(2)O(3) concentration.
In this study, a novel continuous reactor has been developed to produce high quality methyl esters (biodiesel) from palm oil. A microporous TiO2/Al2O3 membrane was packed with potassium hydroxide catalyst supported on palm shell activated carbon. The central composite design (CCD) of response surface methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst amount and cross flow circulation velocity on the production of biodiesel in the packed bed membrane reactor. The highest conversion of palm oil to biodiesel in the reactor was obtained at 70 °C employing 157.04 g catalyst per unit volume of the reactor and 0.21 cm/s cross flow circulation velocity. The physical and chemical properties of the produced biodiesel were determined and compared with the standard specifications. High quality palm oil biodiesel was produced by combination of heterogeneous alkali transesterification and separation processes in the packed bed membrane reactor.
Cage-cultured Asian redtail catfish Hemibagrus nemurus (Valenciennes, 1840), a popular food fish in Southeast Asia, proved to be infected by 3 myxozoan species. All the 3 species belonged to the genus Henneguya: 2 were identified as H. mystusia Sarkar, 1985 and H. hemibagri Tchang et Ma, 1993, while the other was described as H. basifilamentalis sp. n. All plasmodia were found in the gills and were characterised by a specific site selection. H. mystusia formed plasmodia in the multi-layered epithelium between the gill lamellae and in the non-lamellar edge of the gill filaments, while H. hemibagri developed in the capillary network of the lamellae. H. basifilamentalis sp. n. had large oval plasmodia located deep among the filaments just above the gill arch.
Cage-cultured sutchi catfish Pangasius hypophthalmus (Sauvage, 1878), a favourite food fish in Southeast Asia, proved to be infected by 6 myxozoan species. Three species belonged to the genus Hennegoides (H. berlandi, H. malayensis, and H. pangasii), 1 to Henneguya (H. shariffi) and 2 to Myxobolus (M. baskai, and M. pangasii). Five myxozoans infected the gills and 1 was found on the spleen. Myxozoans infecting the gills were characterised by a specific site selection. H. shariffi sp. n. and H. berlandi sp. n. formed plasmodia in the multi-layered epithelium of the gill filaments. Of the 2 vascular species H. pangasii sp. n. developed in the gill arteries, while M. baskai sp. n. infected the capillary network of the gill lamellae. Plasmodia of H. malayensis sp. n. were found inside the cartilaginous gill rays of the filaments. Large plasmodia of M. pangasii sp. n. were located in a groove of the spleen but they affected only the serosa layer covering the spleen.
We describe new myxosporean species from Malaysian fishes cultured in pond farms and net-cages. Myxobolus omari sp. nov. and M. leptobarbi sp. nov. were found in the muscles of Pangasianodon hypophthalmus and Leptobarbus hoevenii, respectively, while plasmodia and spores of Thelohanellus zahrahae sp. nov. and Henneguya daoudi sp. nov. were detected in the gills of Barbonymus gonionotus and Trichogaster trichopterus, respectively. Plasmodia and spores found in these fishes differed from the known myxosporean species in respect of their morphology, tissue tropism and 18S rDNA structure. No major pathological changes were found, but in the future these species might pose a potential threat to more intensified fish culture.
Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO(2)-PbO-Bi(2)O(3) glass host doped with Er(3+)/Yb(3+) ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi(2)O(3) participate with PbO(4) tetragonal pyramids and strongly distort BiO(6) octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.
Deep eutectic solvents (DESs) are green solvents developed as an alternative to conventional organic solvents and ionic liquids to extract nitrogen compounds from fuel oil. DESs based on p-toluenesulfonic acid (PTSA) are a new solvent class still under investigation for extraction/separation. This study investigated a new DES formed from a combination of tetrabutylphosphonium bromide (TBPBr) and PTSA at a 1:1 molar ratio. Two sets of ternary liquid-liquid equilibrium experiments were performed with different feed concentrations of nitrogen compounds ranging up to 20 mol% in gasoline and diesel model fuel oils. More than 99% of quinoline was extracted from heptane and pentadecane using the DES, leaving the minutest amount of the contaminant. Selectivity was up to 11,000 for the heptane system and up to 24,000 for the pentadecane system at room temperature. The raffinate phase's proton nuclear magnetic resonance (1H-NMR) spectroscopy and GC analysis identified a significantly small amount of quinoline. The selectivity toward quinoline was significantly high at low solute concentrations. The root-mean-square deviation between experimental data and the non-random two-liquid (NRTL) model was 1.12% and 0.31% with heptane and pentadecane, respectively. The results showed that the TBPBr/PTSADES is considerably efficient in eliminating nitrogen compounds from fuel oil.
Removal of nitrogen and sulfur compounds from diesel fuel is essential to comply with the increasing stringent regulations. The extraction capability of two deep eutectic solvents, namely, tetrabutylphosphoniumbromide/ethylene glycol, TBPBr/EG, with molar ratio 1:2, and tetrabutylammoniumbromide/ethylene glycol, TBABr/EG, with molar ratio 1:2, in simultaneously extracting basic nitrogen, nonbasic nitrogen, and sulfur compounds represented by pyridine, indoline, and dibenzothiophene (DBT) from n-hexadecane, was investigated. Two pseudo-ternary phase diagrams of (TBPBr/EG + (pyridine + indoline + DBT) + n-hexadecane) and (TBABr/EG + (pyridine + indoline + DBT) + n-hexadecane) were predicted via a conductor-like screening model for real solvents (COSMO-RS) and experimentally validated at 298.15 K and 1 atm. Both solvents showed zero cross-contamination, indicating the suitability of all solvents as extraction solvents. The tie lines obtained for both COSMO-RS and experiments were in agreement and had root-mean-square deviation (RMSD) values of less than 5% for both systems. Selectivity and distribution ratio calculated indicates the suitability of both solvents in extracting sulfur and nitrogen compounds from hexadecane. Two new parameters, namely, extraction efficiency, α, and extraction affinity, β, were introduced to ease the performance comparison of both solvents. TBPBr/EG shows a slightly better performance than TBABr/EG. Other than that, the presence of multiple solutes shows low effects on the performance of these solvents.
An optimal ratio of omega-6 to omega-3 (ω-6/ω-3) polyunsaturated fatty acids (PUFA) in the diet prevents the pathogenesis of many inflammatory diseases. This study aimed to synthesize and characterize ternary oil blends with optimal ω-6/ω-3 ratios using olive (OL), sunflower (SU), and cress (CR) oils. The oxidative stability, thermal profile, fatty acid (FA) and tocopherol compositions, and the physicochemical properties of the blends were used to determine their quality. Oil mixtures were prepared with 2, 3, 4, and 5 ω-6/ω-3 ratios. FA composition and tocopherol content were the most important factors affecting the oxidation and thermal stabilities of the oils. All oil mixtures showed good quality indices. Thus, synthetized oil blends with high oxidative stability, high antioxidant content, optimal ω-6/ω-3 ratios, and recommended FA compositions can influence human health. The composition of healthy oil blends with optimal ω-6/ω-3 ratios was expressed mathematically and depicted graphically in a ternary diagram.
Natural plant extracts offer a promising hope in the prevention/treatment of cancer arising from genetic mutations. This study evaluated in vitro and in vivo mutagenic and antimutagenic effects of aqueous fraction of Myristica fragrans (AFMF) leaves on TA100 strain of Salmonella typhimurium and Mus musculus (Male Swiss albino mice), respectively. The antioxidant activity of AFMF against 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic and flavonoid contents were determined, followed by its phytochemical elucidation using the Ultra Performance Liquid Chromatography technique (UPLC). The mutagenicity of AFMF at 4, 20, 50, 100, 200, 500, and 1000 µg/well was <2.0 in S. typhimurium and the induced micronucleated polychromatic and normochromatic erythrocytes at 500, 1000, 2000, and 4000 mg/kg were not significantly different from the negative control (p≥0.05). The mutagenic activity of benzo[a]pyrene and cyclophosphamide was significantly suppressed above 50.0% throughout the tested concentrations. Fifty percent of the free radicals from DPPH were scavenged by AFMF at 0.11 mg/ml. Total phenolic and flavonoid contents of AFMF were 51.0 mg GAE/g and 27 mg QE/g, respectively. Rutin was elucidated by the UPLC technique, and thereby suspected to be the phytochemical responsible for the observed antimutagenic activity. Thus far, AFMF seems to contain a promising chemotherapeutic agent for the prevention of genetic damage that is crucial for cancer development.
Since its introduction in 1995, nanoimprint lithography has been demonstrated in many researches as a simple, low-cost, and high-throughput process for replicating micro- and nanoscale patterns. Due to its advantages, the nanoimprint lithography method has been rapidly developed over the years as a promising alternative to conventional nanolithography processes to fulfill the demands generated from the recent developments in the semiconductor and flexible electronics industries, which results in variations of the process. Roll-to-roll (R2R) nanoimprint lithography (NIL) is the most demanded technique due to its high-throughput fulfilling industrial-scale application. In the present work, a general literature review on the various types of nanoimprint lithography processes especially R2R NIL and the methods commonly adapted to fabricate imprint molds are presented to provide a clear view and understanding on the nanoimprint lithography technique as well as its recent developments.